Continuous flow moisture analyzer

ABSTRACT

A continuous flow moisture analyzer ( 20 ) includes a coaxial needle ( 34 ) having first and second needle portions ( 36, 38 ). The first needle portion ( 36 ) receives a carrier gas ( 24 ) and expels the carrier gas ( 24 ) through an output orifice ( 60 ). The second needle portion ( 38 ) has an input orifice ( 62 ) for receiving the carrier gas ( 24 ) expelled from the output orifice ( 60 ). A housing ( 40 ) encloses the output orifice ( 60 ) and the input orifice ( 62 ) when the moisture analyzer ( 20 ) is in a standby mode to obtain a baseline moisture content of the carrier gas ( 24 ) within the moisture analyzer ( 20 ). A bottle ( 48 ) retains a sample material ( 50 ). When the analyzer ( 20 ) is in an active mode, the coaxial needle ( 34 ) penetrates a septum ( 52 ) of the bottle ( 48 ) to position the output and input orifices ( 60, 62 ) in the bottle ( 48 ). The carrier gas ( 24 ), expelled from the output orifice ( 60 ), absorbs moisture from the sample material ( 50 ) in the bottle ( 48 ). The expelled carrier gas ( 24 ) carrying the moisture is received at the input orifice ( 62 ) and is transported through the second needle portion ( 38 ) to a moisture sensor ( 70 ) which detects the moisture in the carrier gas ( 24 ).

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to moisture analyzers. Morespecifically, the present invention relates to a continuous flowmoisture analyzer for determining the moisture content in a samplematerial under test.

BACKGROUND OF THE INVENTION

Various manufacturing processes, chemical reactions, and laws attendantcertain industries require that the percentage of certain volatilefluids of interest present within a product be known. Indeed, thedetermination of moisture (or volatile) content in materials is of suchimportance in so many fields that a wide variety of devices andanalytical methods have been developed to provide such information. Onesuch analytical moisture analysis method is a chemical analysis methodknown as the Karl Fischer technique. The Karl Fischer moisture analysistechnique is a method of titrating a test sample with a reagent todetermine trace amounts of water in the test sample. Unfortunately,chemical analysis methods rely on the use of various reagents which maybe toxic. Moreover, such chemical analysis methods usually require veryskilled operators and are often quite time consuming.

Moisture analysis devices include, for example, vacuum ovens andconvection ovens which heat a test sample of the product to atemperature commensurate with the volatile fluid of interest to causeevaporation of such fluid. Devices of this type are often referred to asloss on drying analyzers. Using a loss on drying moisture analyzer, theresulting reduction in weight of the test sample provides data forcomputing the percent by weight of the volatile fluid of interest in thetest sample. Various computational techniques may be employed toforecast the percentage determination based upon the initial weight lossrate. Such computational approximations reduce the time required tocomplete a test without serious derogation of the accuracy of thedetermination. Loss on drying techniques are limited to approximately0.1% minimum moisture loss due to secondary effects such as convectiveair currents, buoyancy effects, and temperature gradients. In addition,loss on drying techniques can sustain some degree of measurement errorrelative to the accuracy of the scale used for weighing the test sample.

Other moisture analysis devices employ sensors that measure the quantityof volatile fluid in a gas stream to determine the amount of volatilefluid in a test sample. For example, one such moisture analyzer includesa test sample heater, a dry carrier gas flow system, and a moisturetransducer. The moisture analyzer heats a sample of test materialcontained in a septum bottle. The dry gas is injected into the septumbottle and absorbs the moisture out of the sample material. The dry gas,carrying the moisture from the sample, is ejected from the septum bottleand transported to the moisture transducer where the moisture content ofthe flowing gas is measured. A processor then integrates the varyingmoisture signal and converts the integrated signal to total moisturecontent. Using the sample weight and the total moisture content value,the moisture concentration in the test sample is subsequentlycalculated.

Unfortunately, problems such as pre-existing moisture levels, transientresponse times, and contamination render the measurement of moisturecontent inaccurate. In one such moisture analyzer, uncontrolled moisturecan be introduced into the dry carrier gas flow system. Thisuncontrolled moisture results in a non-consistent baseline, whichconsequently leads to inaccuracy in the measurement of the moisturecontent in the sample material.

SUMMARY OF THE INVENTION

Accordingly, it is an advantage of the present invention that acontinuous flow moisture analyzer is provided.

It is another advantage of the present invention the continuous flowmoisture analyzer efficiently and accurately determines the moisturecontent in a sample of dry material.

It is another advantage of the present invention that the continuousflow moisture analyzer accurately determines the moisture content in asample material by substantially preventing the introduction ofuncontrolled moisture in the gas flow system of the moisture analyzer.

The above and other advantages of the present invention are carried outin one form by a continuous flow moisture analyzer including a firstneedle portion having a first channel for receiving a carrier gas andhaving an output orifice from the first channel for expelling thecarrier gas and a second needle portion having an input orifice forreceiving the carrier gas expelled from the output orifice and having asecond channel in communication with the input orifice for transportingthe carrier gas. A housing encloses the output orifice and the inputorifice when the moisture analyzer is in a standby mode. A bottleretains a sample material when the moisture analyzer is in an activemode. The bottle has a septum configured to face the housing, the firstand second needle portions penetrating the septum to position the outputand input orifices in the bottle. The carrier gas expelled from theoutput orifice absorbs moisture from the sample material, and a moisturesensor in fluid communication with the second channel detects moisturein the carrier gas.

The above and other advantages of the present invention are carried outin another form by a continuous flow moisture analyzer. The continuousflow moisture analyzer includes a coaxial needle having a first end anda second end. The coaxial needle includes a first needle portion havinga first channel for receiving a carrier gas and having an output orificefrom the first channel for expelling the carrier gas. The coaxial needlefurther includes a second needle portion having an input orifice forreceiving the carrier gas expelled from the output orifice and having asecond channel in communication with the input orifice for transportingthe carrier gas. The output orifice and the input orifice are locatedproximate the second end. A housing encloses the output orifice and theinput orifice when the moisture analyzer is in a standby mode. Thehousing includes a track in nonmoving relation with the coaxial needle,and a sleeve slidably coupled to the track. A bottle retains a samplematerial and is configured to abut the sleeve when the moisture analyzeris in an active mode. The bottle has a septum facing the sleeve. Whenthe bottle abuts the sleeve, the sleeve retracts along the track toallow the coaxial needle to penetrate the septum to position the outputand input orifices in the bottle. The carrier gas expelled from theoutput orifice absorbs moisture from the sample material, and a moisturesensor in fluid communication with the second channel detects themoisture in the carrier gas.

The above and other advantages of the present invention are carried outin yet another form by a continuous flow moisture analyzer. A continuousflow moisture analyzer a first needle portion having a first channel forreceiving a carrier gas and having an output orifice from the firstchannel for expelling the carrier gas and a second needle portion havingan input orifice for receiving the carrier gas expelled from the outputorifice and having a second channel in communication with the inputorifice for transporting the carrier gas. A housing encloses the outputorifice and the input orifice when the moisture analyzer is in a standbymode. The housing includes a track in non-moving relation with thecoaxial needle, and a sleeve sidably coupled to the track. A bottleretains a sample material when the moisture analyzer is in an activemode. The bottle has a septum configured to face the housing. Themoisture analyzer further includes a transport mechanism for conveyingthe bottle toward the housing so that the first and second needleportions penetrate a center portion of the septum to position the outputand input orifices in the bottle. The carrier gas expelled from theoutput orifice absorbs moisture from the sample material, and a moisturesensor in fluid communication with the second channel detects themoisture in the carrier gas.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be derived byreferring to the detailed description and claims when considered inconnection with the Figures, wherein like reference numbers refer tosimilar items throughout the Figures, and:

FIG. 1 shows a block diagram of a continuous flow moisture analyzer inaccordance with a preferred embodiment of the present invention;

FIG. 2 shows a side view of a coaxial needle of the moisture analyzer;

FIG. 3 shows a sectional side view of the coaxial needle of FIG. 2;

FIG. 4 shows a cross-sectional view of the coaxial needle along line 4—4in FIG. 2;

FIG. 5 shows a perspective view of a first side of a housing forenclosing the coaxial needle of the moisture analyzer;

FIG. 6 shows a perspective view of a second side of the housing of FIG.5;

FIG. 7 shows a sectional side view of the housing of FIG. 5 enclosingthe coaxial needle in a standby mode;

FIG. 8 shows a sectional side view of the housing of FIG. 6 with thecoaxial needle located in a bottle retaining a sample material in anactive mode;

FIG. 9 shows a perspective view of a transport mechanism of the moistureanalyzer for conveying the bottle;

FIG. 10 shows a perspective view of an adjustment element of thetransport mechanism of FIG. 9;

FIG. 11 shows a side view of the transport mechanism of FIG. 9 adjustedto convey a first bottle having a first diameter; and

FIG. 12 shows a side view of the transport mechanism of FIG. 9 adjustedto convey a second bottle having a second diameter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a block diagram of a continuous flow moisture analyzer 20in accordance with a preferred embodiment of the present invention.Moisture analyzer 20 is used primarily for determining the moisturecontent, i.e., the volatile liquid such as water, in a solid samplematerial under test. Exemplary solid sample materials include plasticpellets, food products, such as cereal, freeze dried pharmaceuticals,and so forth. Moisture analyzer 20 is configured to evaporate themoisture present within a sample material. This moisture is absorbed bya carrier gas passing over the sample material. The carrier gas istransported to a moisture sensor, which subsequently detects themoisture in the carrier gas.

Moisture analyzer 20 includes a pressure regulator 22 configured toreceive a flow of carrier gas, represented by arrows 24. Carrier gas 24may be dry nitrogen, dry air, or any other gas that can effectivelyabsorb and carry moisture. Pressure regulator 22 provides carrier gas 24to a valve 26 at a predetermined pressure. In a preferred embodiment,the predetermined pressure is approximately one and a half pounds persquare inch.

Valve 26 is a restrictor valve that receives carrier gas 24 output bypressure regulator 22 and provides carrier gas 24 at a controlled flowrate. In particular, valve 26 has an orifice of approximately 0.15 mm(0.006 inches) for controlling the flow rate of carrier gas 24 toapproximately one hundred milliliters per minute.

An output of valve 26 is in communication with a flow sensor 28. Flowsensor 28 measures a mass flow of carrier gas 24 as carrier gas 24passes flow sensor 28. The mass flow is the mass of a fluid substance(e.g., carrier gas 24) that passes a specified unit area in a unitamount of time. Flow sensor 28 has an output in communication with aprocessor 32 for providing a mass flow signal 30, responsive to the flowrate of carrier gas 24, through an analog-to-digital converter (notshown) to a processor 32.

Moisture analyzer 20 further includes a coaxial needle 34 having a firstneedle portion 36 and a second needle portion 38. Coaxial needle 34passes through a sleeve 40 of a housing 42, sleeve 40 being slidablycoupled to a track 44 of housing 42. A transport mechanism 46 conveys abottle 48 toward housing 42. Bottle 48 is configured to retain a samplematerial 50. Bottle 48 includes a septum 52 (see FIG. 8) configured toface housing 42 such that coaxial needle 34 penetrates through septum 52into bottle 48.

A heater 54 surrounds bottle 48 and is configured to heat samplematerial 50 to a predetermined temperature at a predetermined rate toevaporate the volatile liquid from sample material 50. The predeterminedtemperature and rate, controlled by processor 32, depend upon thecharacteristics of both the sample and the volatile liquid of interest.A resistive temperature device (not shown) may be used to read thetemperature of heater 54.

Carrier gas 24 flows from valve 26 via flow sensor 28 to an inlet 56 offirst needle portion 36 of coaxial needle 34. As such, pressureregulator 22 and valve 26 are in fluid communication with first needleportion 36. Inlet 56 is generally located in an inlet/outlet (I/O) block58 of moisture analyzer 20. Carrier gas 24, received at inlet 56 isconveyed through a first channel 59 of first needle portion 36 to anoutput orifice 60.

Carrier gas 24 is expelled from first channel 59 via output orifice 60of first needle portion 36 into bottle 48. Carrier gas 24 absorbsevaporated moisture from sample material 50 as sample material 50 isheated. Carrier gas 24, expelled from output orifice 60 of first needleportion 36, is received at an input orifice 62 of second needle portion38 of coaxial needle 34. Second needle portion 38 includes a secondchannel 64 in communication with input orifice 62 for transportingcarrier gas 24.

Carrier gas 24 is expelled from an outlet 66 of second needle portion 38located in inlet/outlet block 58. Carrier gas 24 flows from secondchannel 64 through outlet 66 to a filter 68. During the heating ofsample material 50 within bottle 48, particulate matter of samplematerial 50 may be inadvertently conveyed by carrier gas 24. Suchparticulate matter may jeopardize the integrity and accuracy of analysisof the moisture in carrier gas 24 and/or undesirably cause particulatematter to be exhausted from moisture analyzer 20 with carrier gas 24. Toeliminate such particulate matter, filter 68 may be employed to filtercarrier gas 24 flowing from outlet 66.

Following filtering at filter 68, carrier gas 24 flows to a relativehumidity sensor 70. Relative humidity sensor 70 is a moisture sensor fordetecting moisture in carrier gas 24. Relative humidity sensor 70 has anoutput in communication with a processor 32 for providing a percentrelative humidity signal 72, responsive to the relative humidity ofcarrier gas 24, through an analog-to-digital converter (not shown) toprocessor 32. In a preferred embodiment, moisture analyzer 20 employs arelative humidity sensor. However, is should be apparent that othermoisture sensors may be used. In addition, a moisture detecting reagentmaybe used as a moisture sensor in an alternative embodiment of thepresent invention.

Processor 32 subsequently computes a moisture content of carrier gas 24as a volume per unit of time in response to mass flow signal 30 receivedfrom flow sensor 28 and percent relative humidity signal 72 receivedfrom moisture sensor 70. Following detection of the moisture content incarrier gas 24, carrier gas 24 is exhausted from continuous flowmoisture analyzer 20.

Controls for the various sequential steps, pressure, flow rates,predetermined temperature and rate, and so forth are performed byprocessor 32. Processor 32 is in communication with an input device 74and an output device 76. Input device 74 can encompass a keypad,keyboard, mouse, pointing device, or other devices providing input toprocessor 32. Such input may include, for example, material sampleidentification, lot or product ID number, test parameters, testduration, and so forth. Output device 76 can encompass a display, aprinter, or other devices providing output from processor 32. Suchoutput may include, material sample identification, test results inparts-per-million, test results in percent moisture, test results intotal micrograms of water, and so forth.

The moisture content of carrier gas 24 is computed relative to abaseline moisture content of carrier gas 24. In other words, processor32 initially computes a moisture content of carrier gas 24 in a standbymode, i.e., prior to coaxial needle 34 penetrating septum 52 (FIG. 8) ofbottle 48. The moisture content of carrier gas 24 is then computed in anactive mode, i.e., after coaxial needle 34 has penetrated septum 52 ofbottle 48. Processor 32 subsequently computes a difference from thebaseline moisture content responsive to the moisture detected during theactive mode to obtain a moisture content of sample material 50.

The structure of continuous flow moisture analyzer 20 substantiallyprevents the entry of uncontrolled moisture into the carrier gas flowportions of analyzer 20. In particular, uncontrolled moisture isprevented from entering analyzer 20 and being detected by relativehumidity sensor 70 through the construction of coaxial needle 34 andhousing 42, as will become readily apparent in the ensuing discussion.

Referring to FIGS. 2-4, FIG. 2 shows a side view of coaxial needle 34 ofmoisture analyzer 20 (FIG. 1). FIG. 3 shows a sectional side view ofcoaxial needle 34, and FIG. 4 shows a cross-sectional view of coaxialneedle 34 along line 4—4 in FIG. 2.

Coaxial needle 34 is a two part needle assembly formed from first needleportion 36 and second needle portion 38. First needle portion 36 is aplunger structure through which first channel 59 is directed from afirst end 78 to a second end 80 of coaxial needle 34. First needleportion 36 exhibits an outer diameter 82 at its widest point proximatesecond end 80.

Second needle portion 38 is generally tube shaped having a sharp pointat second end 80 of coaxial needle 34. Second channel 64 is directedfrom first end 78 to second end 80 of coaxial needle. Second channel 64exhibits an inner diameter 84. Inner diameter 84 is greater than outerdiameter 82 of second needle portion 36, so that first needle portion 36is positioned within second channel 64 to form coaxial needle 34. Thus,first and second needle portions 36 and 38, respectively, of coaxialneedle 34 have a common longitudinal axis 86.

Coaxial needle 34 is shown having one output orifice 60 and two inputorifices 62. However, it should be understood that coaxial needle 34 mayinclude any number of output and input orifices to best accommodate theflow of carrier gas 24 from output orifice 60 to input orifice 62.Output orifice 60 of first needle portion 36 and input orifice 62 ofsecond needle portion 38 are located proximate second end 80 with outputorifice 60 being nearer to second end 80.

Input orifices 62 are longitudinally offset along second needle portion38 from the location of output orifice 60. That is, input orifices 62are located farther away from second end 80 than output orifice 60.Input orifices 62 are also circumferentially offset about second needleportion 38 from the location of output orifice 60. That is, inputorifices 62 are rotated about the circumference of second needle portion38 approximately ninety degrees out of alignment with output orifice 60.This longitudinal and circumferential offset of input orifice 62relative to output orifice 60 causes carrier gas 24 to effectivelycirculate in bottle 48 (FIG. 1) to absorb moisture from sample material50 prior to carrier gas 24 being received at input orifice 62.

First channel 59 exhibits a first cross-sectional gas flow area 88.Likewise, second channel 64 exhibits a second cross-sectional gas flowarea 90. Second gas flow area 90 is substantially equivalent to firstcross-sectional gas flow area. This equivalent size results inmaximizing the flow of carrier gas 24 with minimum pressure drop.

FIGS. 2-4 show coaxial needle 34 in a preferred embodiment of thepresent invention. However, it should be understood that alternatestructures of coaxial needle 34 may be envisioned. For example, theshape and placement of second needle portion 38 may be exchanged withthe shape and placement of first needle portion 36. In such aconfiguration, second needle portion 38 may be located within a channelof first needle portion 36. Alternatively, first and second needleportions 36 and 38, respectively, may be two separate needles. As such,each of first and second needle portions 36 and 38 would include sharppoints for penetrating septum 52 (FIG. 8).

Referring to FIGS. 5 and 6, FIG. 5 shows a perspective view of a firstside 92 of sleeve 40 of housing 42 for enclosing coaxial needle 34 ofmoisture analyzer 20 (FIG. 1). FIG. 6 shows a perspective view of asecond side 94 of sleeve 40 of housing 42. First side 92 includes afirst opening 96 through which coaxial needle 34 extends. Second side 94includes a second opening 98 through which coaxial needle 34 protrudeswhen moisture analyzer 20 (FIG. 1) is in the active test mode.

As discussed previously, housing 42 includes sleeve 40 slidably coupledto track 44. In a preferred embodiment, housing 42 includes two tracks44. Tracks 44 may be coupled to inlet/outlet block 58 (FIG. 1) so thattracks 44 do not move relative to coaxial needle 34. A mounting fixture100 is coupled to sleeve 40. Mounting fixture 100 includes passages 102through which each of tracks 44 are directed. Sleeve 40 is then able toslide along tracks 44, the motion of which is represented by abi-directional arrow 104.

FIG. 7 shows a sectional side view of sleeve 40 of housing 42 enclosingcoaxial needle 34 in a standby mode. A first O-ring 106 is located infirst opening 96. Second opening 98 is located in a cover portion 108 ofsleeve 40 and a second O-ring 110 is located in second opening 98.Coaxial needle 34, surrounded by first O-ring 106 blocks first opening96, and the second end 80 of coaxial needle 36, surrounded by secondO-ring 110 blocks second opening 110. This blockage results in a sealedchamber 112 being formed within sleeve 40.

Thus, as shown in FIG. 7, when moisture analyzer 20 (FIG. 1) is in thestandby mode, output orifice 60 and input orifice 62 are located withinsealed chamber 112. As such, carrier gas 24 expelled at output orifice60 is received at input orifice 62 without having absorbed uncontrolledmoisture. Accordingly, the baseline moisture content of moistureanalyzer 20 (FIG. 1) may be ascertained in the standby mode.

FIG. 8 shows a sectional side view of housing 42 with coaxial needle 34located in bottle 48 in an active mode. In the active mode, second end80 of coaxial needle 34 protrudes through second opening 98 andpenetrates septum 52 in a lid 114 of bottle 48. This penetration isaccomplished when lid 114 abuts cover portion 108 of sleeve 40. Inresponse to the contact, sleeve 40 retracts by sliding along tracks 44(FIGS. 5-6) so that coaxial needle 34 leaves sealed chamber 112 andpenetrates septum 52. Thus, when moisture analyzer,20 (FIG. 1) is in theactive mode, output orifice 60 and input orifice 62 are positionedwithin bottle 48. As such, carrier gas 24, expelled at output orifice60, is received at input orifice 62 having absorbed moisture evaporatedfrom sample material 50 as sample material 50 is heated.

The abutment of lid 114 with cover portion 108. results in minimal ornegligible exposure of output orifice 60 and input orifices 62 touncontrolled moisture from outside of moisture analyzer 20. Thus, thebaseline moisture content determined in standby mode is a valid baselinefrom which a difference of moisture content may be computed in order toobtain a moisture figure for sample material 50.

FIG. 9 shows a perspective view of transport mechanism 46 of moistureanalyzer 20 (FIG. 1) for conveying bottle 48 (FIG. 8) into abutment withsleeve 40 (FIG. 8) of housing 42. Like sleeve 40 (FIGS. 5-6) of housing42, transport mechanism 46 may be slidably fixed to tracks 44 to align acenter axis 116 of transport mechanism 46 with longitudinal axis 86(FIG. 2) of coaxial needle 34 (FIG. 2). In addition, transport mechanism46 may be transported along tracks 44 to an internal cavity (not shown)of moisture analyzer 20 (FIG. 1) in which the moisture analysis willoccur. Transport mechanism 46 includes a top 118, a base 120, andretaining rods 122 disposed therebetween. Top 118 is configured to facehousing 42 (FIG. 1), and base 120 includes an adjustment element 124.Retaining rods 122 are movably coupled to adjustment element 124 and top118.

Each of retaining rods 122 has an elbow 126 at each of a first end 128and a second end 130. When adjustment element 124 is actuated, retainingrods 122 concurrently pivot relative to top 118 and base 120 to bringelbows 126 toward center axis 116 of transport mechanism 46. Likewise,when adjustment element 124 is further actuated, retaining rods 122concurrently pivot relative to top 118 and base 120 to bring elbows 126away from center axis 116 of transport mechanism 46. In such a manner,transport mechanism 46 can convey bottles of varying diameters.

FIG. 10 shows a perspective view of adjustment element 124 of transportmechanism 46 (FIG. 9). Adjustment element 124 includes gears 128, eachof which are coupled to one of retaining rods 122. Gears 128 includeteeth 130 that mesh with corresponding teeth 132 of an actuating gear134. When actuating gear 134 is put into action by movement of a lever136, gears 128 concurrently move in order to affect the pivoting actionof retaining rods 122.

Although adjustment element 124 is described using a gear based system.It should be understood that other mechanisms may be used to cause theconcurrent pivoting action of retaining rods 122.

Referring to FIGS. 11-12, FIG. 11 shows a side view of transportmechanism 46 adjusted to convey a first bottle 48′ having a firstdiameter 138. FIG. 12 shows a side view of transport mechanism 46adjusted to convey a second bottle 48″ having a second diameter 140.First diameter 138 of first bottle 48′ differs from second diameter 140of second bottle 48″, in that first diameter 138 is larger than seconddiameter 140. The concurrent pivoting action of retaining rods 122allows transport mechanism to readily adapt to bottles of varying sizes.Moreover, the concurrent pivoting action or retaining rods 122 resultsin bottles 48′ and 48″ maintaining alignment with coaxial needle 34(FIG. 8) so that coaxial needle 34 penetrates septum 52.

In standby mode operation, moisture analyzer 20 (FIG. 1) is activatedwith coaxial needle 34 located in sealed chamber 112 (FIG. 7) of sleeve40 (FIG. 7). When moisture analyzer 20 is activated, carrier gas 24flows into sealed chamber 112 via first channel 59 (FIG. 3) of firstneedle portion 36 (FIG. 3). Carrier gas 24 is expelled from outputorifice 60 (FIG. 7) into sealed chamber 112, and received at inputorifice 62 of second needle portion 38. Carrier gas 24 is subsequentlytransported via second channel 64 (FIG. 3) to relative humidity sensor70 to determine a baseline moisture content of continuous flow moistureanalyzer 20. Moisture analyzer 20 may remain activated continuously inwhich case carrier gas 24 will flow through the system continuously.Alternatively, moisture analyzer 20 may be activated some predeterminedperiod of time prior to performing moisture analysis of sample material50 (FIG. 1).

Active mode operation is initiated following standby mode operation sothat carrier gas 24 continuously flows during the entirety of standbymode and active mode operations. In active mode, bottle 48, or either offirst and second bottles 48′ and 48″, is placed in transport mechanism46 (FIG. 9). Lever 136 of adjustment element 124 (FIG. 9) is actuated tocause retaining rods 122 to pivot to retain bottle 48. Bottle 48 ispositioned in retaining rods 122 so that lid 114 is positioned in acenter opening of top 118 of transport mechanism 46.

In this position, transport mechanism 46 conveys bottle 48 into moistureanalyzer 20′ toward housing 42 (FIG. 8) and into proximity of heater 54(FIG. 1). When lid 114 abuts cover portion 108 (FIG. 8) of sleeve 42,sleeve 42 retracts along tracks 44 causing coaxial needle 34 (FIG. 8) topenetrate septum 52 (FIG. 8) and enter bottle 48. Once coaxial needle 34enters bottle 48 carrier gas 24 continuously flowing from output orifice60 (FIG. 8) begins absorbing moisture evaporating from sample material50 (FIG. 8) in bottle 48.

Carrier gas 24 carrying moisture from sample material 50 is received atinput orifices 62 and transported via second channel 64 (FIG. 3) ofcoaxial needle 34 (FIG. 3) to relative humidity sensor 70 (FIG. 1) wherethe moisture in carrier gas 24 is detected. Carrier gas 24 carryingmoisture from sample material 50 is subsequently exhausted from analyzer20. As discussed previously, mass flow signal 30 (FIG. 1) and percentrelative humidity signal 72 (FIG. 1) are used by processor 32 (FIG. 1)to obtain a moisture figure related to the amount of volatile liquid, ormoisture, in sample material 50.

In summary, the present invention teaches of a continuous flow moistureanalyzer that utilizes a carrier gas such as nitrogen or dry oxygen in asealed gas flow system. The sealed gas flow system is accomplishedthrough a sleeve for enclosing a coaxial needle during a standby mode sothat baseline moisture content readings may be obtained The sleeve isretractable, in an active mode, through the contact of a sealed bottleagainst the sleeve. As the sleeve retracts, the coaxial needlepenetrates the septum of a bottle. The coaxial needle located in thebottle then employs the carrier gas to absorb evaporated volatileliquid, which is subsequently detected by a moisture sensor. Thisresults in an analyzer that efficiently and accurately determines themoisture content in a sample of test material. In addition, the moistureanalyzer accurately determines the moisture content in the samplematerial by substantially preventing the introduction of uncontrolledmoisture in the gas flow system of the moisture analyzer.

Although the preferred embodiments of the invention have beenillustrated and described in detail, it will be readily apparent tothose skilled in the art that various modifications may be made thereinwithout departing from the spirit of the invention or from the scope ofthe appended claims.

What is claimed is:
 1. A continuous flow moisture analyzer comprising: afirst needle portion having a first channel for receiving a carrier gasand having an output orifice from the first channel for expelling thecarrier gas; a second needle portion having an input orifice forreceiving the carrier gas expelled from the output orifice and having asecond channel in communication with the input orifice for transportingthe carrier gas; a housing for enclosing the output orifice and theinput orifice when the moisture analyzer is in a standby mode so thatthe carrier gas can flow through the first channel and the secondchannel in the standby mode; a bottle for retaining a sample materialwhen the moisture analyzer is in an active mode, the bottle having aseptum configured to face the housing, the first and second needleportions penetrating the septum to position the output and inputorifices in the bottle, the carrier gas expelled from the output orificeabsorbing moisture from the sample material; and a moisture sensor influid communication with the second channel for detecting the moisturein the carrier gas.
 2. A continuous flow moisture analyzer as claimed inclaim 1 further comprising a pressure regulator in fluid communicationwith the first needle portion for providing the carrier gas to the firstchannel at a predetermined pressure.
 3. A continuous flow moistureanalyzer as claimed in claim 1 further comprising a valve in fluidcommunication with the first needle portion for providing the carriergas to the first channel at a predetermined flow rate.
 4. A continuousflow moisture analyzer as claimed in claim 1 further comprising a massflow sensor in fluid communication with the first needle portion formeasuring a flow rate of the carrier gas entering the first channel. 5.A continuous flow moisture analyzer as claimed in claim 4 wherein: themoisture sensor is a relative humidity sensor; and the analyzer furthercomprises a processor in communication with each of the relativehumidity sensor and the mass flow sensor for computing a moisturecontent of the carrier gas with respect to a unit of time.
 6. Acontinuous flow moisture analyzer as claimed in claim 1 furthercomprising a processor in communication with the moisture sensor, theprocessor computing a baseline moisture content of the carrier gas inthe standby mode, the processor further computing a moisture content ofthe carrier gas in the active mode, and the processor determining adifference between the moisture content and the baseline moisturecontent to obtain a moisture figure of the sample material.
 7. Acontinuous flow moisture analyzer as claimed in claim 1 wherein thefirst and second needle portions have a common longitudinal axis.
 8. Acontinuous flow moisture analyzer as claimed in claim 1 wherein: thefirst needle portion exhibits an outer diameter; and the second channelof the second needle portion exhibits an inner diameter, the innerdiameter being greater than the outer diameter, and the first needleportion being positioned within the second channel.
 9. A continuous flowmoisture analyzer as claimed in claim 8 wherein the first and secondneedle portions form a coaxial needle having an end configured topenetrate the septum of the bottle, the output orifice is proximate theend, and the input orifice is longitudinally offset along a longitudinalaxis of the coaxial needle relative to the output orifice such that theinput orifice is a greater distance from the end than the outputorifice.
 10. A continuous flow moisture analyzer as claimed in claim 8wherein the first and second needle portions form a coaxial needlehaving a circumference, and the input orifice is circumferentiallyoffset about the circumference relative to the output orifice such thatthe input orifice is out of alignment with the output orifice.
 11. Acontinuous flow moisture analyzer as claimed in claim 1 wherein: thefirst channel exhibits a first cross-sectional gas flow area; and thesecond channel exhibits a second cross-sectional gas flow area, thesecond cross-sectional gas flow area being substantially equivalent tothe first cross-sectional gas flow area.
 12. A continuous flow moistureanalyzer as claimed in claim 1 wherein: the bottle is configured to abutthe housing; and the housing comprises: a track in non-moving relationwith the first and second needle portions; and a sleeve slidably coupledto the track such that the sleeve retracts when the bottle abuts thesleeve to allow the first and second needle portions to penetrate theseptum.
 13. A continuous flow moisture analyzer as claimed in claim 1wherein:. the first and second needle portions form a coaxial needlehaving a first end and a second end, the output orifice and the inputorifice being located proximate the second end; and the housingcomprises a sleeve having a first side and a second side, the coaxialneedle extending through a first opening in the first side, and thesecond end of the coaxial needle blocking a second opening in the secondside of the sleeve to form a sealed chamber within the sleeve in whichthe output orifice and the input orifice reside in the standby mode. 14.A continuous flow moisture analyzer as claimed in claim 13 wherein thehousing further comprises: a first O-ring located in the first openingand surrounding the first end of the coaxial needle; and a second O-ringlocated in the second opening and surrounding the second end of thecoaxial needle.
 15. A continuous flow moisture analyzer as claimed inclaim 13 wherein the second end of the coaxial needle protrudes throughthe second opening into the bottle in the active mode.
 16. A continuousflow moisture analyzer as claimed in claim 1 further comprising atransport mechanism for conveying the bottle toward the housing so thatthe first and second needle portions penetrate a center portion of theseptum.
 17. A continuous flow moisture analyzer as claimed in claim 16wherein the transport mechanism is adjustable for conveying the bottlehaving a first diameter and for conveying a second bottle having asecond diameter, the second diameter differing from the first diameter.18. A continuous flow moisture analyzer as claimed in claim 16 whereinthe transport mechanism comprises: a base including an adjustmentelement; a top configured to face the housing; and retaining rods forholding the bottle, the retaining rods being movably coupled to theadjustment element of the base and movably coupled to the top, theretaining rods having an elbow at each of a first end and a second end,wherein when the adjustment element is actuated, the retaining rodsconcurrently pivot relative to the base and the top to bring the elbowsnear a center axis of the transport mechanism, and when the adjustmentelement is further actuated, the retaining rods concurrently pivotrelative to the base and the top to bring the elbows away from a centeraxis of the transport mechanism.
 19. A continuous flow moisture analyzeras claimed in claim 1 further comprising a heater surrounding the bottlefor heating the sample material when the moisture analyzer is in theactive mode.
 20. A continuous flow moisture analyzer as claimed in claim1 further comprising a filter interposed between the second channel ofthe second needle portion and the moisture sensor.
 21. A continuous flowmoisture analyzer comprising: a coaxial needle having a first end and asecond end, the coaxial needle including: a first needle portion havinga first channel for receiving a carrier gas and having an output orificefrom the first channel for expelling the carrier gas; and a secondneedle portion having an input orifice for receiving the carrier gasexpelled from the output orifice and having a second channel incommunication with the input orifice for transporting the carrier gas,the output orifice and the input orifice being located proximate thesecond end; a housing for enclosing the output orifice and the inputorifice when the moisture analyzer is in a standby mode, the housingincluding: a track in non-moving relation with the coaxial needle; and asleeve slidably coupled to the track; a bottle for retaining a samplematerial and configured to abut the sleeve when the moisture analyzer isin an active mode, the bottle having a septum facing the sleeve, andwhen the bottle abuts the sleeve, the sleeve retracts along the track toallow the coaxial needle to penetrate the septum to position the outputand input orifices in the bottle, the carrier gas expelled from theoutput orifice absorbing moisture from the sample material; and amoisture sensor in fluid communication with the second channel fordetecting the moisture in the carrier gas.
 22. A continuous flowmoisture analyzer as claimed in claim 21 wherein: the first needleportion exhibits an outer diameter; and the second channel of the secondneedle portion exhibits an inner diameter, the inner diameter beinggreater than the outer diameter, and the first needle portion beingpositioned within the second channel.
 23. A continuous flow moistureanalyzer as claimed in claim 21 wherein: the first channel exhibits afirst cross-sectional gas flow area; and the second channel exhibits asecond cross-sectional gas flow area, the second cross-sectional gasflow area being substantially equivalent to the first gas. flowcross-sectional area.
 24. A continuous flow moisture analyzer as claimedin claim 21 wherein: the sleeve includes a first side and a second side,the coaxial needle extending through a first opening in the first side,and the second end of the coaxial needle blocking a second opening inthe second side of the sleeve to form a sealed chamber within the sleevein which the output orifice and the input orifice reside in the standbymode.
 25. A continuous flow moisture analyzer as claimed in claim 24wherein the housing further comprises: a first O-ring located in thefirst opening and surrounding the first end of the coaxial needle; and asecond O-ring located in the second opening and surrounding the secondend of the coaxial needle.
 26. A continuous flow moisture analyzer asclaimed in claim 24 wherein the second end of the coaxial needleprotrudes through the second opening into the bottle in the active mode.27. A continuous flow moisture analyzer as claimed in claim 24 furthercomprising a transport mechanism for conveying the bottle toward thehousing so that the first and second needle portions penetrate a centerportion of the septum.
 28. A continuous flow moisture analyzercomprising: a first needle portion having a first channel for receivinga carrier gas and having an output orifice from the first channel forexpelling the carrier gas; a second needle portion having an inputorifice for receiving the carrier gas expelled from the output orificeand having a second channel in communication with the input orifice fortransporting the carrier gas; a housing for enclosing the output orificeand the input orifice when the moisture analyzer is in a standby mode,the housing including: a track in non-moving relation with the first andsecond needle portions; and a sleeve slidably coupled to the track; abottle for retaining a sample material when the moisture analyzer is inan active mode, the bottle having a septum configured to face thehousing; a transport mechanism for conveying the bottle toward thehousing so that the first and second needle portions penetrate a centerportion of the septum to position the output and input orifices in thebottle, the carrier gas expelled from the output orifice absorbingmoisture from the sample material; and a moisture sensor in fluidcommunication with the second channel for detecting the moisture in thecarrier gas.
 29. A continuous flow moisture analyzer as claimed in claim28 wherein the transport mechanism is adjustable for conveying thebottle having a first diameter and for conveying a second bottle havinga second diameter, the second diameter differing from the firstdiameter.
 30. A continuous flow moisture analyzer as claimed in claim 28wherein the transport mechanism comprises: a base including anadjustment element; a top configured to face the housing; and retainingrods for holding the bottle, the retaining rods being movably coupled tothe adjustment element of the base and movably coupled to the top, theretaining rods having an elbow at each of a first end and a second end,wherein when the adjustment element is actuated, the retaining rodsconcurrently pivot relative to the base and the top to bring the elbowsnear a center axis of the transport mechanism, and when the adjustmentelement is further actuated, the retaining rods concurrently pivotrelative to the base and the top to bring the elbows away from a centeraxis of the transport mechanism.